1. Field of the Invention
This invention relates to internal combustion engines, and more particularly concerns apparatus which utilizes combustion-generated heat to improve fuel efficiency and secure additional advantages.
2. Description of the Prior Art
Numerous engine economizer systems have been disclosed in the prior art. Various methods have been employed in attempts to increase fuel economy, promote more efficient combustion, and utilize the heat generated as a by-product of combustion. Eriksen U.S. Pat. No. 2,746,440 discloses a carburetion apparatus adapted to exchange heat from engine exhaust gases with the liquid gasoline. The gasoline is heated to vaporize a gaseous fuel supply which is substituted for the normal atomized fuel/air mixture. Similarly, Dwyre U.S. Pat. No. 3,713,429 discloses a system whereby gasoline is heated by either exhaust gasses or coolant fluid from the engine. Simultaneously, air is injected into the heated fuel to initiate the atomization prior to the fuel reaching the carburetor.
Fuel additives have been disclosed for improving engine efficiency. For example, in U.S. Pat. No. 4,068,639 to Cook discloses the blending of liquid propane with gasoline and air in the carburetor, and utilizes exhaust back pressure to control the fuel mixture and flow.
Many systems have been disclosed which recirculate exhaust gases in a fuel/air mixture which is returned to the intake manifold of an engine, thereby heating the mixture to enhance combustion and reduce hydrocarbon emissions. The valve disclosed in U.S. Pat. No. 3,990,418 to Nohira and Tanaka is utilized in a system of this nature in order to prevent carburetor icing, a common occurrence due to the rapid cooling of water vapor contained in the exhaust gases.
Another method of providing greater engine economy has been the introduction of water vapor into the fuel/air mixture. Loby U.S. Pat. No. 3,908,613 utilizes special water mist injection nozzles to add a precisely metered mist of water vapor into each cylinder. The water vapor has several beneficial effects. It inhibits detonation, whereby a greater compression of fuel/air/water mixture may be achieved. The harmful mechanical degradation created by detonation within the cylinders under compression depletes power and reduces engine life. The water vapor also improves the electrical conductivity of the fuel/air mixture, thereby enhancing complete ignition of the mixture. The added water vapor further serves to accelerate expansion of gases in the cylinder during the power stroke, and reduces the operating temperature of the cylinder head. A leaner mixture of fuel may be used because the fuel mixture is often maintained richer than optimum for combustion purposes in order to prevent undesirable temperature rises in the cylinder heads. The Loby patent however, discloses a radically improved engine design which precludes the use of such water vapor induction in standard internal combustion engines.
The prior art discloses means for utilizing both exhaust gases and radiator coolant fluid as means for heating fuel. Although the engine heat is being utilized, the engine oil is still circulating in the engine at elevated temperatures. At higher temperature, motor oil is susceptible to breakdown in viscosity, and thereby has diminished friction-reducing capability. The higher temperatures also promote rapid degradation of the oil, thereby reducing its useful life.
It is therefore an object of the present invention to provide an engine economizer system which will reduce the fuel consumption of an internal combustion engine per unit of work achieved.
It is another object of the present invention to provide a system of the aforesaid nature which will significantly reduce the level of hydrocarbon and carbon monoxide emissions from an internal combustion engine.
It is a further object of this invention to provide a system of the aforesaid nature which will increase the useful life of an internal combustion engine, its spark plugs, valves, motor oil, and exhaust system.
It is yet another object of the present invention to provide a system of the aforesaid nature which is adaptable to a variety of commercially available engines.
It is still another object of this invention to provide a system of the aforesaid nature which is easy to install and maintain, has a minimal number of moving parts, is durable, and amenable to low cost manufacture.